Medical Case Study 3: AI-Guided Personalized Cancer Treatment

Precision Medicine in Oncology | AI in Healthcare Lesson 11

Patient Background

Patient: Dr. Sarah Kim, 42-year-old physician (family medicine)
Diagnosis: Stage IIIB HER2-positive breast cancer
Medical History: Previously healthy, no significant medical conditions
Family History: Mother had breast cancer at age 67, survived after treatment
Professional Context: As a physician herself, Sarah was highly knowledgeable about cancer treatment but faced the emotional challenge of becoming a patient

The Challenge of Cancer Treatment Selection

Cancer is not a single disease—it's hundreds of different diseases with vastly different behaviors and treatment responses. Even within one type (like breast cancer), tumors can be molecularly distinct and require different approaches.

The One-Size-Fits-All Problem:

Traditional Cancer Treatment Approach (Pre-Personalized Medicine):

Why Do Patients Respond Differently?

The challenge: How do oncologists predict which treatment will work for which patient?

Enter Precision Medicine and AI

Precision medicine (also called personalized medicine) means selecting treatments based on the individual characteristics of each patient's cancer and their genetic profile, rather than treating everyone the same.

AI's Role in Precision Oncology:

In Sarah's case, her oncology team used IBM Watson for Oncology combined with Foundation Medicine's genomic profiling to guide treatment selection.

Sarah's Treatment Journey: Traditional vs. AI-Guided Approach

What Traditional Approach Would Have Been:

Based on Sarah's cancer type (HER2-positive breast cancer, Stage IIIB), standard protocol would be:

  1. Neoadjuvant chemotherapy (before surgery): Doxorubicin + Cyclophosphamide, followed by Paclitaxel + Trastuzumab (Herceptin)
  2. Surgery to remove tumor
  3. Additional Trastuzumab for one year
  4. Radiation therapy

Expected outcome: 70-75% chance of no cancer recurrence in 5 years (based on population statistics)

The AI-Guided Personalized Approach:

Step 1: Comprehensive Genomic Profiling

Tumor biopsy sent to Foundation Medicine for FoundationOne CDx test, which sequences 324 cancer-related genes. Results revealed:

  • HER2 amplification (expected, confirmed diagnosis)
  • PIK3CA mutation (unexpected finding in 30% of breast cancers)
  • High tumor mutational burden (TMB-H)
  • PD-L1 expression (immune checkpoint protein)

Significance: These findings suggested additional treatment opportunities beyond standard protocol

Step 2: AI Analysis by IBM Watson for Oncology

Watson processed:

  • Sarah's complete genomic report
  • Her medical history and lab values
  • Current evidence from 15+ million pages of medical literature
  • Clinical trial data on treatment combinations
  • Outcomes data from similar patients

Watson's Analysis Revealed:

  • Sarah's PIK3CA mutation makes her tumor potentially resistant to standard Trastuzumab alone
  • Her high TMB and PD-L1 expression suggest she could benefit from immunotherapy
  • A clinical trial combining HER2-targeted therapy + PIK3CA inhibitor + immunotherapy was recruiting
  • This triple combination had shown 91% response rate in patients with similar genetic profiles

Step 3: Treatment Decision

Sarah's oncology team met to discuss Watson's recommendations. They considered:

  • Option A: Standard protocol (70-75% no-recurrence rate)
  • Option B: AI-recommended clinical trial protocol (predicted 85-90% response based on her specific mutations)

After extensive discussion with Sarah, the team enrolled her in the clinical trial. The personalized protocol was:

  • Trastuzumab + Pertuzumab (dual HER2 blockade)
  • Alpelisib (PIK3CA inhibitor) - targeted therapy for her specific mutation
  • Pembrolizumab (immunotherapy checkpoint inhibitor) - leverages her tumor's PD-L1 expression
  • Paclitaxel (standard chemotherapy)

Step 4: Treatment Monitoring with AI

Throughout treatment, AI algorithms monitored:

  • Tumor response via serial imaging
  • Blood markers (circulating tumor DNA)
  • Side effects and quality of life metrics
  • Predicted optimal surgery timing

After 16 weeks of therapy, imaging showed:

  • 95% tumor shrinkage (exceptional response)
  • No detectable cancer spread to lymph nodes
  • AI predicted optimal surgery window approaching

Step 5: Surgery and Pathology

Sarah underwent surgery. Pathology analysis revealed:

  • Pathologic complete response (pCR): No living cancer cells found in removed tissue
  • This is the best possible outcome and strongly predicts long-term survival
  • pCR rate with standard treatment: 50-60%
  • pCR rate with Sarah's personalized protocol: 85-90% (in clinical trial data)

The Science Behind the AI Recommendations

How Watson for Oncology Works:

Watson is a cognitive computing system that uses natural language processing and machine learning to analyze unstructured data (medical literature, clinical guidelines, trial results) and structured data (patient records, lab values, genomic data).

The Process:

  1. Input: Oncologist enters patient information - age, cancer type/stage, genetic mutations, medical history, lab values
  2. Literature Analysis: Watson analyzes:
    • 300+ medical journals
    • 200+ textbooks
    • 15+ million pages of text
    • Clinical trial databases
    • Treatment guidelines (NCCN, ASCO, etc.)
  3. Pattern Recognition: Identifies patients in literature with similar characteristics and analyzes their treatment outcomes
  4. Evidence Synthesis: Ranks treatment options by strength of evidence:
    • Recommended: Supported by strong evidence for this patient profile
    • For Consideration: Evidence suggests potential benefit but less certain
    • Not Recommended: Evidence suggests minimal benefit or potential harm
  5. Output: Detailed report with treatment options, supporting evidence, clinical trial opportunities, and predicted outcomes

Foundation Medicine Genomic Profiling:

This test sequences hundreds of cancer-related genes to identify:

In Sarah's case, without genomic profiling, oncologists would not have known about:

Outcome and Sarah's Perspective

Two Years Post-Treatment:

Sarah's Reflection:

"As a physician, I understood the science behind precision medicine intellectually. But experiencing it as a patient was transformative. The traditional approach would have given me good odds—maybe 70-75% chance of no recurrence. But why settle for 'good enough' when genomic profiling and AI could identify a better option specifically for my tumor's genetic makeup?"

"The AI didn't make the decision—my oncology team did, in partnership with me. But Watson identified a treatment combination that my doctors hadn't initially considered. It flagged the clinical trial and explained why my specific genetic profile made me an ideal candidate. Without that AI analysis connecting my tumor's mutations to the right therapy, I would have received standard treatment and faced higher recurrence risk."

"I know I was fortunate—I had excellent insurance, access to a major cancer center with cutting-edge technology, and the medical knowledge to advocate for myself. That's the equity challenge we face: How do we ensure ALL cancer patients, not just the privileged few, can access precision medicine?"

Comparing Approaches: Data Analysis

Aspect Traditional Protocol AI-Guided Precision Approach
Treatment Selection Basis Cancer type and stage only Type, stage, AND tumor genetics, AND patient characteristics
Data Analyzed Treatment guidelines (100-200 pages) 15M+ pages literature, thousands of trials, genomic databases
Time to Select Treatment 1-2 hours oncologist review Minutes for AI + 2-3 hours team discussion
Predicted Response Rate (for Sarah's genetic profile) 70-75% 85-90%
pCR (Complete Response) Rate 50-60% 85-90%
Clinical Trial Consideration If oncologist aware of relevant trial Automatic matching to appropriate trials
Cost Standard treatment ~$100,000-150,000 Genomic testing ~$5,000 + treatment ~$150,000-200,000
Accessibility Available at most cancer centers Limited to major academic centers, expensive

Important Considerations and Limitations

Benefits of AI-Guided Precision Medicine:

Challenges and Limitations:

Ethical Questions:

Case Study Analysis Worksheet

Student Name: ___________________ Date: _______________

Question 1: Understanding Precision Medicine

In your own words, explain what "precision medicine" means. How is it different from the traditional "one-size-fits-all" approach to cancer treatment?

Question 2: AI's Multiple Roles

Identify and explain at least three specific ways AI contributed to Sarah's cancer treatment. For each, describe what the AI analyzed and what insights it provided.

Question 3: Genomic Information Impact

The genomic profiling revealed Sarah's tumor had a PIK3CA mutation and high tumor mutational burden. Explain how these genetic findings changed her treatment options. What would have been missed without this genetic information?

Question 4: Statistical Reasoning

Compare the predicted outcomes for traditional treatment (70-75% no-recurrence rate) versus AI-guided personalized treatment (85-90% response rate). If you were Sarah, would these statistical differences be significant enough to influence your treatment decision? Why or why not?

Question 5: Human vs. AI Capabilities

Watson for Oncology can analyze 15+ million pages of medical literature. Why is this capability important in cancer treatment? What can the AI do that human oncologists cannot? What can human oncologists do that AI cannot?

Question 6: Healthcare Equity Challenge

Sarah notes that she "had excellent insurance, access to a major cancer center with cutting-edge technology, and the medical knowledge to advocate for herself." She asks: "How do we ensure ALL cancer patients, not just the privileged few, can access precision medicine?" Propose at least two specific solutions to address this equity challenge.

Question 7: Cost-Benefit Analysis

AI-guided precision medicine costs more upfront (genomic testing ~$5,000) but may lead to better outcomes. Should health insurance be required to cover this testing for all cancer patients? Consider both financial and ethical arguments in your answer.

Question 8: Thinking About Decision-Making

Sarah's case involved the AI identifying a treatment option that her doctors "hadn't initially considered." What does this tell us about the role of AI in medical decision-making? Should doctors always follow AI recommendations? Why or why not?

Discussion Questions for Groups

  1. The case study mentions that most clinical trials have historically enrolled white participants. How might this affect the accuracy of AI recommendations for patients from other racial or ethnic backgrounds? What should be done to address this?
  2. If genomic testing reveals a mutation with no known treatment, should patients still be told about it? What are the psychological impacts of knowing your cancer's genetics when it doesn't change treatment?
  3. Imagine you're a policy maker. Would you require that all cancer patients receive genomic profiling and AI treatment recommendations, or should it remain optional? Explain your reasoning.
  4. Sarah was a physician and could understand the complex scientific information about her treatment. How should oncologists communicate AI recommendations to patients who don't have medical knowledge?
  5. In 20 years, precision medicine may be standard for all cancers. What changes in healthcare infrastructure, insurance, and education would be needed to make this happen equitably?

Vocabulary Terms